Powdery zeolite of Type A, which can be employed as a phosphate substitute in washing agent, because of its small particle size represents a clumpy powder which is inclined to agglomerate. It is difficult to mix this zeolite powder with the rest of components of the washing agent to form a homogeneous powder. The problem is aggravated by the fact that the finished mixture has a tendency to separate into its components again.
In order to avoid this mixing problem, there have already been added zeolite granulates to the spray dried washing agent components. These zeolite granulates are produced, inter alia, by spray drying an aqueous suspension of the zeolite powder with addition of further components of the washing agent.
It is known to treat zeolite suspension with sodium sulfate, spray dry to zeolite granulates and to mix in the remaining washing agent components (cf. European published patent application No. 870, Kali Chemie). These known zeolite granulates have the disadvantage that they do not fulfill the requirements placed on them. Thus, it is necessary that the zeolites have an undiminished calcium binding capacity, a good redispersibility and a good transportation and particle stability. Of especial importance is the lowest possible dust content.